Directional drilling tool



Jan. 16,1968 R, J. FARRIS ETAL 3,363,704

DIRECTIONAL DRILLING TOOL 2 Sheets-Shet 1 Filed March 24, 1966 405. cf Farr/J Jamar M 771' INVENTORJ ATTOF Wi' V Jan. 16, 1968 R. J. FARRIS ET AL 3,363,704

DIRECTIONAL DRILLING TOOL Filed March 24, 1966 2 Sheets-Sheet 2 fiofofi (f. Farr/J 4/0/2791 M Tag/0r v fa aiz 'l V. Gar/eff JNVENTORS United States Patent 3,363,704 DIRECTIONAL DRILLING TOOL Ralph J. Farris, James M. Taylor, and Eddy W. Garrett, New Iberia, La., assignors to Whipstock, Inc., Midland, Tex., a corporation of Texas Filed Mar. 24, 1966, Ser. No. 537,142 8 Claims. (Cl. 175-76) This invention relates to improvements in directional drilling tools and refers more particularly to that type of tool which is made up in the drill string for rotation therewith and adapted to impart a series of forces tending to move the bit in one direction as the drill string is rofated.

This invention is an improvement upon the invention shown in United States Letters Patent 3,092,188 issued June 4, 1963.

The invention of said Patent 3,092,188 has proven to be of great utility in directional drilling of wells. The tool is expensive, however, both to build and maintain and an object of the present invention is to provide an effective directional drilling tool which is much cheaper to manufacture and, due to its ruggedness and simplicity, to maintain.

Another object is to provide an efiective directional drilling tool which can impart more than a single force tending to move the bit upon each rotation of the tool.

Another object is to provide an effective directional drilling tool which is relatively short and which may place all of the effective working parts at a single level along the longitudinal axis of the tool body.

Another object is to provide a directional drilling tool in which the force is imparted to the drill string tending to move the bit in one direction very close to the bit itself.

Another object is to provide a directional drilling tool which may serve as a bottom stabilizer of the drill string.

Other and further objects will appear from the specification, drawings and claims.

The drawings illustrate one preferred embodiment of the invention. It is contemplated that other embodiments and modifications may be made within the scope of the appended claims and the drawings and specification describing same should therefore be interpreted in an illustrative rather than a limiting sense. In the drawings:

FIG. 1 is a longitudinal sectional view, with parts removed for clarity, illustrating the preferred embodiment of the invention;

FIG. 2 is a longitudinal elevational view taken at about 90 to FIG. 1 and shown partially in section;

FIG. 3 is a cross-sectional view taken along the line 3-3 in FIG. 1 in the direction of the arrows;

FIG. 4 is a view taken along the line 44 in FIG. 1 in the direction of the arrows; and

FIG. 5 is a view similar to FIG. 4, but looking down, and showing the bore engaging rockers in place and illustrating the tool in a bore hole.

In the drawings, the tool body has fastening means 10a and 1% at its ends for securing the body in a drill string to become a part thereof. Usually and preferably the tool is mounted immediately adjacent the bit, and may replace the bottom stabilizer which often is run. It is contemplated that the tool body may be the body of the bit itself, but this is not usually preferred because of the relatively short life of the bit.

The body may be a relatively short sub for example, somewhat less than four feet long. The body is circular throughout most of its length and the major diameter may be that of the drill collar to which it is secured. The body is tubular providing the flow passage 100 for circulating the drilling fluid to the bit.

The body or sub 10 provides a support for the active 3,363,794 Patented Jan. 16, 1968 elements which provide the directional drilling forces for pushing the hit one way or another. For this purpose the body is provided with one or a plurality of recesses in its periphery for mounting the rockers 11, the number of recesses depending on the number of rockers used. The ro'ckers are pivotally mounted on pivot pin 12 whose ends are retained in bearings 13 and 14. These bearings are blocks for receiving the ends of pivot pin 12. The blocks have changes as shown at 14a for fitting in the grooves 10d formed in the body. The retainer blocks 15 and 16 are secured in the upper end of the recesses to retain the bearings and pivot pin l2 in place. Openings a provide means for securing the retainer blocks in the body by means of retainer pins 15a and 16a. When retainer blocks 15 and 16 are removed, the bearing blocks 13 and 14 may he slid into or out of place. Set screws 17 and 18 may be provided to secure the key pins 15a and 16a respectively, in place. The mounting assembly may include bushings and washers 19 and 20. In the embodiment shown, two such rocker arm mounting assemblies are provided. Each are identical and it is contemplated that more of such units may be employed.

Semi-circular guard shields 10 and vided above and below the rockers 11. upper and lower surfaces, respectively tion against impact for the rockers as ered into and pulled from a well bore. of the periphery of the shields should of the drill string but less than that which the tool is to be used.

The rockers are best shown in FIG. 5. Each rocker 11 is provided with arms 11a and 11b which are adapted to swing around the pivot pin 12. The free end of each arm provides a part that is adapted to move substantially radially toward and away from the longitudinal axis of the i ody as the rockers are pivotally moved. Each part contains a hardened wear-resisting surface 11c and 11d which are adapted to engage and rub against the wall of the bore hole. Tungsten carbide or other suitable hard material may be used to resist wear of this wall-engaging portion.

Means are provided for limiting the movement of the parts or arms 11a and 11b. This includes the abutment surfaces 21 and 22 adapted to be engaged by arms 11a and 11b, respectively, to limit pivotal movement of the arms. Preferably the arrangement is such that the wall engaging surface of one arm will extend further outwardly from the longitudinal axis of the body than will the wall-engaging surface of the other arm at the two limits of rotation of the rocker. This may be accomplished by providing the surfaces 21 and 22 as included in a cord and making one arm slightly longer than the other. As seen in FIG. 5 rocker 11 is shown in full line and dotted line positions. In the full line position, the arm 11:: is extended outwardly and the arm 11b is retracted. Because of the means for limiting the extent to which the arm 11a may extend outwardly relative to the extent arm llb may extend outwardly, means is provided for exerting a force or push against the wall of the well bore, the reaction of which tends to move the sub and therefore the bit attached to it, in one direction or the other relative to the low side of the hole. The dotted line position of rocker 11 illustrates the degree that contact surface 11]; may be pushed relative to the possible extension of arm 11a. It is seen that arm 11b may extend from the axis of the body a greater distance than the radius of the drill bit which forms the well bore 23. On the other hand, surface 110 of arm He cannot extend as far outwardly from the longitudinal axis of the body as does 11d of arm 11!). Thus when surface 110 is moved past the low side of the hole it is pushed inwardly into its receiving recess in the body until the force exerted by 11d engaging the bore hole wall overcomes this force. The net result is to push 1.0g may be pro- They have tapered to provide protecthe tools are low- The greatest radius be greater than that of a drill bit with the body to the left of the low side of the bore hole. However, upon further rotation of the device arm 11d, as it passes the lower side of the hole, will be forced against surface 22 and surface 11c will not be forced into contact with the bore hole wall to the right of the low side of the hole. This is because the arrangement is such that it does not extend far enough outwardly from the longitudinal axis of the body in its fully extended position to engage the wall of the bore hole.

While mechanical means are shown to provide the parts which move substantially radially of the body relative to its axis, it is contemplated that hydraulic means may be included for providing these parts. In any event, the arrangement is such that the movement of one part outwardly is accompanied by inward movement of the other part, and one part is capable of moving a somewhat greater distance from the body axis than the other part.

Due to the radial extent of guard shields 1'81 and g substantially filling the bore hole, thus restricting the fiuid flow past the working elements of the sub, grooves 24 and 25, extending longitudinally of the device and parallel to its axis, are provided. They by-pass drilling fluid past the sub. These grooves extend through the shields 10; and 10g to provide adequate fluid passage.

It is believed that the operation of the apparatus is apparent from the foregoing description. The body is made up into the drill string and either end may be attached to the bit. In the arrangement shown the device will have a tendency to cause the tool to move or walk to the left relative to the low side of the hole. The rotation of drill tools is usually in a clockwise direction looking down so that visualizing clockwise rotation of the body in FIG. 5, wall engaging surface 110 will be caused to engage the low side of the hole ahead of surface 11d. Inasmuch as the weight of the drill collars above the body tends to push the tool against the low side of the hole, this force will cause rocker 11 to move part 110 inwardly toward the longitudinal axis of the body. At the same time wall engaging surface 11d will be moved outwardly to engage the wall of the hole. Thus a force is imparted on the body tending to move the body to the left relative to the low point or side of the bore hole. As the next rocker arm moves its leading edge toward the low side of the hole another force will be exerted on the body tending to move it to the left. These repeated forces occur each time a part 11c moves past the low side of the hole. There is no counteracting force however, tending to move the body to the right as part 11d passes the low side of the hole because part he is not moved out far enough to engage the wall of the hole.

In order to cause the tool to walk to the right, the tool may merely be reversed end for end so that the lower end ltla is secured to the lower end of the drill collar string and the upper end 10b is secured to the bit. This will reverse the arrangement of rockers so that as surface 110 passes the low side of the hole, it is trailing, in a rotational sense, end 11d. Then as arm 11a is rotated inwardly, surface llld is moved into contact or engagement with the left side of the bore hole wall thus tending to provide a force urging the body to the right. Successive rotations of rocker past the low side of the hole apply successive forces to the tool tending to urge it to the right. The ends of arms 11a and b are tapered whereby they tend to slide over the formation rather than to dig into it.

While it is contemplated that usually only a single level of rockers or pusher parts will need to be provided it is possible, where further forces are required, to utilize more than one level of such means. If this is done, it is contemplated that if desired the successive levels of wall engaging parts may be staggered circumferentially with respect to each other so as to provide a more or less continuous tendency to urge the tool in one direction or they may be aligned circumferentially so as to provide the same number of impulses as a single layer, but of greater bearing area. This may be of particular help in drilling relatively soft shales where the pusher means will tend to push in to the relatively soft shale of the bore hole. By providing a greater bearing area the net effective push is greater.

It is seen that the ends and objects of the invention have been accomplished. A directional drilling tool has been provided that may be manufactured at relatively low cost and which is especially rugged, and requires little maintenance which may be inexpensively performed. The construction is such that the same device may be used to cause walking to the right or to the left. The arrangernent is such that a moment arm advantage is provided because arm 11a is longer than arm 11b thus magnifying the effect of the force urging the tool against the low side of the hole.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the device.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

1. A directional drilling tool for use in rotary drilling of Wells comprising a tubular body with means for connecting it in a drilling string; means including two parts mounted on the body at substantially the same level along its longitudinal axis for substantially radial movement relative thereto and spaced circumferentially about the body so that the paths of movement of the parts are angularly disposed relative to the body, said means relating the movements of the parts to each other so that inward movement of one part imparts outward movement of the other part relative to the longitudinal axis of the body; each of the parts having a surface for engaging the wall of a bore hole; means limiting the movement of one of said parts outwardly from the longitudinal axis of the body relative to the maximum outward movement of the other of said parts to provide for the wall engaging surface of one of said parts to move somewhat outwardly from the periphery of the body when the second of said parts is in its innermost position and the second of said parts to move a greater distance outwardly from said axis of the body when the first of said parts is in its innermost position relative to said body axis.

2. The directional drilling tool of claim 1 wherein the maximum outermost position of the wall engaging surface of the first of said parts from the body axis is no greater than the radius of a bit with which the drilling tool is adapted for use and the outermost position of the wall engaging portion of the second part relative to said body axis is at least as great as the radius of a bit with which the drilling tool is adapted for use.

3. The directional drilling tool of claim 1 wherein the ends of an arm pivotally mounted on the body provide the two parts and the wall engaging surfaces thereof.

4. A directional drilling tool for use in rotary drilling of wells comprising a tubular body with means for connecting it in a drill string; a rocker, means mounting the rocker on the body for pivotal movement transversely of the longitudinal axis of the body with the arms of the rocker extending on two sides of the pivot at substantially the same level along the longitudinal axis of the body; means limiting pivotal movement of the rocker in one rotational sense to permit a first one of the arms, that will swing away from the body, from swinging outwardly from said axis of the body a distance greater than the radius of a bit with which the drilling tool is adapted for use; and means limiting pivotal movement of the rocker in the opposite rotational sense to permit the sec- 0nd of said arms, that will swing away from the body, to swing outwardly from said axis of the body to an eX- tent at least as great as the radius of a bit with which the drilling tool is adapted for use; whereby upon rotation of the body Within a drill hole when the first arm passes over the low side of the hole the second of said arms is forced outwardly to engage the wall of the bore hole to tend to force the tool away from the side of the bore hole wall from the location of engagement of the second arm with the wall of the bore hole.

5. The directional drilling tool of claim 4 wherein the means for limiting movement of the rocker are surfaces on the body which in cross-section would lie on a cord and the first arm is longer than the second arm whereby upon rocking of the rocker the first arm can not move as far outwardly from the axis of the body as does the second arm.

6. The directional drilling tool of claim 4 wherein a plurality of rockers are mounted on said body and arranged symmetrically about the circumference of the body when viewed in cross-section along a plane intersecting said rockers, said rockers being located substantially at the same level along the longitudinal axis of said body.

7. A directional drilling tool as defined in claim 4 wherein the periphery of the body is recessed to provide by-pass passages for drilling fluid, the recesses spanning the longitudinal extent of said rocker.

8. The directional drilling tool of claim 4 wherein said body is provided with circular guard shields above and below said rocker, the radius of said guard shields being greater than the main portion of the body but less than the radius of a bit with which the drilling tool is adapted for use.

References Cited UNITED STATES PATENTS 2,712,434 7/1955 Giles, et al. 175-73 2,745,635 5/1956 Zublin 175-76 2,891,769 6/1959 Page et a1 175-76 3,092,188 6/1963 Faries et al 176--76 3,154,156 10/1964 Moore et al. 175-76 CHARLES E. OCONNELL, Primary Examiner. DAVID H. BROWN, Examiner. 

1. A DIRECTIONAL DRILLING TOOL FOR USE IN ROTARY DRILLING OF WELLS COMPRISING A TUBULAR BODY WITH MEANS FOR CONNECTING IT IN A DRILLING STRING; MEANS INCLUDING TWO PARTS MOUNTED ON THE BODY AT SUBSTANTIALLY THE SAME LEVEL ALONG ITS LONGITUDINAL AXIS FOR SUBSTANTIALLY RADIAL MOVEMENT RELATIVE THERETO AND SPACED CIRCUMFERENTIALLY ABOUT THE BODY SO THAT THE PATHS OF MOVEMENT OF THE PARTS ARE ANGULARLY DISPOSED RELATIVE TO THE BODY, SAID MEANS RELATING THE MOVEMENTS OF THE PARTS TO EACH OTHER SO THAT INWARD MOVEMENT OF THE PART IMPARTS OUTWARD MOVEMENT OF THE OTHER PART RELATIVE TO THE LONGITUDINAL AXIS OF THE BODY; EACH OF THE PARTS HAVING A SURFACE FOR ENGAGING THE WALL OF A BORE HOLE; MEANS LIMITING THE MOVEMENT OF ONE OF SAID PARTS OUTWARDLY FROM THE LONGITUDINAL AXIS OF THE BODY RELATIVE TO THE MAXIMUM OUTWARD MOVEMENT OF THE OTHER OF SAID PARTS TO PROVIDE FOR THE WALL ENGAGING SURFACE OF ONE OF SAID PARTS TO MOVE SOMEWHAT OUTWARDLY FROM THE PERIPHERY OF THE BODY WHEN THE SECOND OF SAID PARTS IS IN ITS INNERMOST POSITION AND THE SECOND OF SAID PARTS TO MOVE A GREATER DISTANCE OUTWARDLY FROM SAID AXIS OF THE BODY WHEN THE FIRST OF SAID PARTS IS IN ITS INNERMOST POSITION RELATIVE TO SAID BODY AXIS. 